Lighting, Light Fixtures, Ceiling and Exhaust Fans - 2 lights - 1 switch - not working...

I'm stumped on this electrical. House is knob and tube. Here is what I have.

1 existing light with 1 black and 1 red wire connected to 3-way light switch that works fine. I'm trying to connect another light with 12/2 wire to use the same light switch.

I connected:

1 black (knob & tube) + 1 black (12/2) (both wirenutted), with pigtail connecting to the switch
1 red connected to the terminal, 1 white connected to the terminal (both on same side of switch)

Here is what happens;

When the switch is OFF, both lights appear dimly lit. When the switch is ON, the old light turns on normally, and the new light is completely off and does nothing. What am I doing wrong? Please help! I would be greatly appreciative.

Thanks so much.

When you have K&T (and often even when you don't), you can almost never extend the circuit from the switch. There is no neutral present in the switch box. You must extend from the light, not from the switch. Put it back the way it was and start over.